Sony Corporation

Nippon Motorola, Ltd.

Akira Sanpei

Kanji Murano

Yasuhito Eguchi

Kazuharu Yanagihara

Masayuki Sato

Hitoshi Okada

Toshio Narushima

Kazuo Honda

Takayuki Aita

Hiroshi Ogata

Hajime Tamiya

A control device includes a controller causing a plurality of cell blocks each configured of one or plurality of secondary battery cells and connected in series to be charged with a cell balance, and the controller includes a detector detecting a voltage of each of the cell blocks, an updater sequentially updating a maximum voltage of the detected voltage of each of the cell blocks, and a discharger discharging a cell block among the plurality of cell blocks, the cell block with a voltage range between the detected voltage and the updated maximum voltage within a discharge target voltage range defined in advance.

Control device and method and power supply device

A method and an apparatus for charging a lithium-ion based rechargeable battery in a short time is provided. A terminal voltage of the rechargeable battery is compared with a predetermined first set voltage Vwhile charging the rechargeable battery with a constant current; pulse charging is performed in which charging is halted after the rechargeable battery is charged with the constant current only during a predetermined first set time Twhen the terminal voltage becomes the first set voltage Vor more; both an elapsed time An from the start of the halt and a terminal voltage Bn at the elapsed time An are measured a plurality of times during the halt of charging in the pulse charging and the terminal voltage Bn is compared with a predetermined second set voltage V; whether or not the terminal voltage drops to the second set voltage Vor less is presumed based on measurement results of the elapsed time An and the terminal voltage Bn in the case where the terminal voltage Bn is higher than the second set voltage Vwhen the elapsed time An reaches a predetermined second set time T; both the pulse charging and the presumption of the terminal voltage are repeated when presumed that the terminal voltage drops to the second set voltage Vor less; and charging is ended when presumed that the terminal voltage does not drop to the second set voltage Vor less.

Rechargeable battery charging method and apparatus

Circuit for preventing overcharge and overdischarge of secondary batteries is disclosed. Overcharge detecting comparators COMP2 and COMP4 each having a hysteresis circuit 1 are connected between positive and negative electrodes of series-connected secondary batteries Abat and Bbat, and overdischarge detecting comparators COMP1 and COMP3 each having a hysteresis circuit 2 are connected also between the above electrodes. Transistors T1, T2 and a resistor R are connected between the batteries for overflow of overcharge and balance of overdischarge. Upon detection of any overcharge by the comparator COMP2 or COMP4, the charge current is interrupted by a transistor T6, and simultaneously the overcharge overflow is discharged by the hysteresis circuit until the battery voltage is lowered to the hysteresis voltage. And after the discharge, the transistor T6 is turned on to resume recharging the batteries. Meanwhile, upon detection of any overdischarge by the comparator COMP1 or COMP3, the discharge current is interrupted by a transistor T5. Thus the overcharge and the overdischarge can be balanced by the hysteresis circuits 1 and 2 respectively.

Circuit for preventing overcharge and overdischarge of secondary

A battery protection circuit has a condition detecting circuit which detects a voltage across a secondary cell or cells and compares the detected voltage with a reference voltage to detect an overdischarged condition or an overcharged condition of the secondary cell or cells. A control unit controls a first switching element for cutting off a discharging current and a second switching element for cutting off a charging current based on a detected condition of the secondary cell or cells. A third switch element cuts off electric power supplied to the condition detecting circuit. The third switch element is rendered nonconductive when the overdischarged condition is detected by the condition detecting circuit.

Battery protection circuit

Circuit groups for preventing a battery from being deteriorated in efficiency due to a charging and discharging of each of secondary batteries is incorporated in a battery protection circuit for protecting a plurality of batteries connected in series to thereby extend a life of the battery. The battery protection circuit incorporates therein power down means for extending a time in which a voltage of a remaining capacity becomes 0V as much as possible by causing a current to flow only in the minimum circuit when the battery is overdischarged. Also, when a trouble such as a momentary overcurrent or the like is detected, the circuit can be prevented from set in the power down mode.

Battery charge control circuit

An overcharge preventing device and an overdischarge preventing device for a nonaqueous electrolyte secondary battery having voltage detectors and are provided to respectively detect terminal voltages of batteries connected in series. A switch is provided in series to the batteries between a common terminal and a charge terminal. When the terminal voltage of at least one of the batteries exceeds a battery design voltage in charging the batteries, the switch is turned off in response to an output from the corresponding voltage detectors, thereby cutting off a charging current. Further, a voltage detector is provided to detect a terminal voltage of the series connected batteries. A switch is provided in series to the batteries between the common terminal and a discharge terminal. When the terminal voltage of the batteries becomes equal to or less than a set voltage in discharging the batteries, the switch is turned off in response to an output from the voltage detector, thereby cutting off a discharging current.

Overcharge preventing device and overdischarge preventing device for a

A method of charging a secondary battery by means of a constant voltage power source for supplying a limited current. The method includes a first step of charging the secondary battery until a predetermined condition is reached, and a second step of further charging the secondary battery for a predetermined period of time after the predetermined condition is reached. Accordingly, overcharge of the secondary battery can be surely prevented.

Charging method for secondary battery

A device for detecting and displaying residual capacity of a battery comprises a comparator comparing detection voltages set to predetermined values and open circuit voltage. The device further contains circuitry to compensate the difference of the open circuit voltage and the closed circuit voltage of the battery. Thus the device can detect the residual capacity of the battery under conditions both with and without the external load.

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Fukushima, Japan

Akira Sanpei